package nl.connectedit.swiss.service;

import lombok.RequiredArgsConstructor;
import lombok.extern.java.Log;
import nl.connectedit.swiss.domain.EventType;
import nl.connectedit.swiss.domain.StandingsEntry;
import nl.connectedit.swiss.domain.Status;
import nl.connectedit.swiss.domain.TournamentStatus;
import nl.connectedit.swiss.domain.entity.*;
import nl.connectedit.swiss.dto.ResultDto;
import nl.connectedit.swiss.repository.TournamentRepository;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;

import static nl.connectedit.swiss.service.ServiceUtil.*;

@Service
@RequiredArgsConstructor
@Log
public class TournamentPlayService {

  private final TournamentRepository tournamentRepository;

  private final StandingsService standingsService;

  public Tournament startRound(Tournament tournament, Long roundId) {
    getRound(tournament, roundId).setStatus(Status.IN_PROGRESS);
    tournament.setStatus(TournamentStatus.ONGOING);
    tournamentRepository.save(tournament);
    return tournament;
  }

  public Tournament finishRound(Tournament tournament, Long roundId) {
    getRound(tournament, roundId).setStatus(Status.FINISHED);
    tournamentRepository.save(tournament);
    return tournament;
  }

  public Tournament finishGroup(Tournament tournament, Long groupId) {
    var group = getGroup(tournament, groupId);
    group.setStatus(Status.FINISHED);

    checkForEventCompletion(tournament, group.getType());

    tournamentRepository.save(tournament);
    return tournament;
  }

  private void checkForEventCompletion(Tournament tournament, EventType type) {
    Group group1 = null;
    Group group2 = null;
    Event event = null;

    for (var e : tournament.getEvents()) {
      if (e.getType() == type) {
        if (e.getGroups().size() != 2) {
          return;
        }
        group1 = e.getGroups().getFirst();
        if (group1.getStatus() != Status.FINISHED) {
          return;
        }

        group2 = e.getGroups().getLast();
        if (group2.getStatus() != Status.FINISHED) {
          return;
        }
        event = e;
      }
    }

    var finalsGroup = new Group();
    finalsGroup.setName(type.getText());
    finalsGroup.setType(type);
    finalsGroup.setStatus(Status.IN_PROGRESS);
    finalsGroup.setEvent(group1.getEvent());

    var standings1 = standingsService.getStandings(group1.getRounds(), group1.getTeams());
    var standings2 = standingsService.getStandings(group2.getRounds(), group2.getTeams());

    var team1_1 = standings1.get(0).getTeam();
    var team1_2 = standings1.get(1).getTeam();
    var team2_1 = standings2.get(0).getTeam();
    var team2_2 = standings2.get(1).getTeam();

    team1_1.getGroups().add(finalsGroup);
    team1_2.getGroups().add(finalsGroup);
    team2_1.getGroups().add(finalsGroup);
    team2_2.getGroups().add(finalsGroup);

    finalsGroup.setTeams(List.of(team1_1, team1_2, team2_1, team2_2));

    var finalsRound = new Round();
    finalsRound.setGroup(finalsGroup);
    finalsRound.setStatus(Status.NOT_STARTED);
    finalsRound.setName("Finales");
    finalsRound.setIsFinalsRound(Boolean.TRUE);

    var match1 = new Match();
    match1.setRound(finalsRound);
    match1.setType(type);
    match1.setStatus(Status.NOT_STARTED);
    match1.setPlayed(false);
    match1.setTeam1(standings1.get(0).getTeam());
    match1.setTeam2(standings2.get(0).getTeam());

    var match2 = new Match();
    match2.setRound(finalsRound);
    match2.setType(type);
    match2.setStatus(Status.NOT_STARTED);
    match2.setPlayed(false);
    match2.setTeam1(standings1.get(1).getTeam());
    match2.setTeam2(standings2.get(1).getTeam());

    finalsRound.setMatches(List.of(match1, match2));
    finalsGroup.setRounds(List.of(finalsRound));
    event.getGroups().add(finalsGroup);
  }

  public Tournament reopenGroup(Tournament tournament, Long groupId) {
    getGroup(tournament, groupId).setStatus(Status.IN_PROGRESS);
    tournamentRepository.save(tournament);
    return tournament;
  }

  public Tournament newRound(Tournament tournament, Long groupId) {
    var group = getGroup(tournament, groupId);

    var standings = standingsService.getStandings(group.getRounds(), group.getTeams());
    var remainingTeams = standings.stream()
      .map(StandingsEntry::getTeam)
      .collect(Collectors.toCollection(ArrayList::new));

    var round = new Round();
    round.setName("Ronde " + (group.getRounds().size() + 1));
    round.setGroup(group);
    round.setStatus(Status.NOT_STARTED);

    if (remainingTeams.size() % 2 == 1) {
      var playersNotToBeDrawnOut = tournament.getDrawnOutPlayers();
      playersNotToBeDrawnOut.addAll(tournament.getPlayersPlayingOnlyOneEvent());
      var tryPosition = remainingTeams.size() - 1;
      do {
        var tryDrawOutTeam = remainingTeams.get(tryPosition);
        if (!playersNotToBeDrawnOut.contains(tryDrawOutTeam.getPlayer1()) && (tryDrawOutTeam.getPlayer2() == null || !playersNotToBeDrawnOut.contains(tryDrawOutTeam.getPlayer2()))) {
          remainingTeams.remove(tryDrawOutTeam);
          round.setDrawnOut(tryDrawOutTeam);
          break;
        }
        tryPosition--;
      } while(true);
    }

    var matches = tryMatches(remainingTeams, group).reversed();

    for (var match : matches) {
      match.setType(group.getType());
      match.setStatus(Status.NOT_STARTED);
      match.setPlayed(false);
      match.setRound(round);
    }

    round.setMatches(matches);

    printRound(round, standings);

    group.getRounds().add(round);

    tournamentRepository.save(tournament);
    return tournament;
  }

  private void printRound(Round round, List<StandingsEntry> standings) {
    for (var match: round.getMatches()) {
      log.info("%s - %s".formatted(
        String.valueOf(standings.stream().filter(entry -> entry.getTeam().equals(match.getTeam1())).map(StandingsEntry::getPosition).findFirst().get()),
        String.valueOf(standings.stream().filter(entry -> entry.getTeam().equals(match.getTeam2())).map(StandingsEntry::getPosition).findFirst().get())));
    }
  }

  private static class ConflictInDrawException extends RuntimeException {}

  private List<Match> tryMatches(List<Team> remainingTeams, Group group) {
    var newMatches = new ArrayList<Match>();
    if (remainingTeams.isEmpty()) {
      return newMatches;
    }
    var newMatch = new Match();
    newMatch.setTeam1(remainingTeams.getFirst());
    for (var opponentIndex = 1; opponentIndex < remainingTeams.size(); opponentIndex++) {
      if (!findPreviousMatchOccurence(newMatch.getTeam1(), remainingTeams.get(opponentIndex), group)) {
        newMatch.setTeam2(remainingTeams.get(opponentIndex));
      } else {
        log.info("Wedstrijd %s - %s kwam al eerder voor.".formatted(newMatch.getTeam1().toString(), remainingTeams.get(opponentIndex).toString()));
        continue;
      }
      var newRemainingTeams = getRemainingTeams(remainingTeams, opponentIndex);
      if (newRemainingTeams.size() == 1) {
        newMatches.add(newMatch);
        break;
      } else {
        try {
          newMatches.addAll(tryMatches(newRemainingTeams, group));
          newMatches.add(newMatch);
          break;
        } catch (ConflictInDrawException ignored) {
        }
      }
    }
    if (newMatch.getTeam2() == null) {
      log.info("Geen tegenstander gevonden voor %s.".formatted(newMatch.getTeam1().toString()));
      throw new ConflictInDrawException();
    }

    return newMatches;
  }

  private List<Team> getRemainingTeams(List<Team> remainingTeams, int opponentIndex) {
    var newRemainingTeams = new ArrayList<Team>();
    for (var remainingTeamIndex = 1; remainingTeamIndex < remainingTeams.size(); remainingTeamIndex++) {
      if (remainingTeamIndex == opponentIndex) continue;
      newRemainingTeams.add(remainingTeams.get(remainingTeamIndex));
    }
    return newRemainingTeams;
  }

  private boolean findPreviousMatchOccurence(Team team1, Team team2, Group group) {
    for (var round : group.getRounds()) {
      for (var match : round.getMatches()) {
        if ((Objects.equals(match.getTeam1(), team1) && Objects.equals(match.getTeam2(), team2))
           || (Objects.equals(match.getTeam1(), team2) && Objects.equals(match.getTeam2(), team1))) {
          return true;
        }
      }
    }
    return false;
  }

  public Tournament startMatch(Tournament tournament, Long matchId, Long court, Long counter) {
    var match = getMatch(tournament, matchId);
    match.setStatus(Status.IN_PROGRESS);
    match.setStartTime(LocalDateTime.now());
    match.setCourt(court);

    var countingPlayer = getPlayer(tournament, counter);
    countingPlayer.setCounting(true);
    match.setCounter(countingPlayer.getPlayer());

    tournamentRepository.save(tournament);
    return tournament;
  }

  private TournamentPlayer getPlayer(Tournament tournament, Long playerId) {
    for (var tournamentPlayer : tournament.getTournamentPlayers()) {
      if (playerId.equals(tournamentPlayer.getPlayer().getId())) {
        return tournamentPlayer;
      }
    }
    return null;
  }

  public Tournament stopMatch(Tournament tournament, Long matchId) {
    var match = getMatch(tournament, matchId);
    match.setStatus(Status.NOT_STARTED);
    match.setStartTime(null);
    match.setCourt(null);

    var countingPlayer = getPlayer(tournament, match.getCounter().getId());
    countingPlayer.setCounting(false);
    match.setCounter(null);

    tournamentRepository.save(tournament);
    return tournament;
  }

  public Tournament saveResult(Tournament tournament, Long matchId, ResultDto result) {
    var match = getMatch(tournament, matchId);
    if (match.getGames().isEmpty()) {
      match.setEndTime(LocalDateTime.now());
      match.setStatus(Status.FINISHED);
      match.setPlayed(true);
    }
    match.getGames().clear();
    match.getGames().addAll(resultToGames(result, match));

    var counter = match.getCounter();
    if (counter != null) { // match was already saved, this is a correction
      var countingPlayer = getPlayer(tournament, counter.getId());
      countingPlayer.setCounting(false);
      countingPlayer.incrementCounts();
      match.setCounter(null);
    }

    tournamentRepository.save(tournament);
    return tournament;
  }

  private List<Game> resultToGames(ResultDto result, Match match) {
    var games = new ArrayList<Game>();
    for (var game : result.getGames()) {
      if (game.getScore1() != null) {
        games.add(Game.builder()
          .score1(game.getScore1())
          .score2(game.getScore2())
          .match(match)
          .build());
      }
    }

    return games;
  }

  public void updatePaid(Tournament tournament, Long playerId, Boolean paid) {
    var tournamentPlayer = tournament.getTournamentPlayers()
      .stream()
      .filter(player -> player.getPlayer().getId().equals(playerId))
      .findFirst()
      .get();

    tournamentPlayer.setPaid(paid);

    tournamentRepository.save(tournament);
  }

  public void updatePresent(Tournament tournament, Long playerId, Boolean present) {
    var tournamentPlayer = tournament.getTournamentPlayers()
      .stream()
      .filter(player -> player.getPlayer().getId().equals(playerId))
      .findFirst()
      .get();

    tournamentPlayer.setPresent(present);

    tournamentRepository.save(tournament);
  }

}